The present invention relates to a resistor circuit, an oscillation circuit, and the like.
A CR oscillation circuit is used as a circuit which generates a clock signal used in an integrated circuit device. The CR oscillation circuit includes a feedback resistor, a feedback capacitor, and a plurality of stages of inverter circuits.
The frequency of the clock signal generated by the CR oscillation circuit is set based on the resistance of the feedback resistor and the capacitance of the feedback capacitor. Therefore, it is necessary to accurately adjust the resistance of the feedback resistor in order to increase the accuracy of the frequency of the clock signal generated. A resistor circuit having fuse elements may be used as the feedback resistor. Specifically, the resistance of the feedback resistor is variably adjusted by blowing (melting) the fuse element using a laser or the like so that the desired clock frequency is achieved. Patent Document 1 (JP-A-2005-19989) discloses related-art technology relating to a fuse element.
When using a resistor circuit having fuse elements, the chip area of the integrated circuit device increases as the layout area of the resistor circuit increases. When using a polysilicon wire as a wire provided across a guard ring formed to enclose the arrangement region of the fuse elements, the adjustment accuracy of the resistance of the resistor circuit deteriorates due to the parasitic resistance of the polysilicon wire.